It has an area of 4,443km², making it the largest Belgian province. At around a quarter of a million residents, it is also the province with the smallest population, making it the most sparsely populated province in an otherwise very densely populated country.

The Arelerland or Arlon region (in red on the following map of the province) alongside the border with the neighbouring Grand-Duchy of Luxembourg has the particularity that many residents speak Luxembourgish instead of the Walloon (French) dialect(s) spoken elsewhere in the province.